1. Field of the Invention
This invention relates to a system and method for the retrieval or accessing of a desired frame from a plurality of frames carried on a roll film on which various information is recorded.
2. Description of the Prior Art
In conventional methods for retrieving film frames, e.g., from microfilm would on a reel, a driving motor's direction of rotation is controlled by the output of a comparator which compares the output of a counter counting the number of frames of the film or reading the frame number of the film with the output of another counter storing the number of the desired frame of the film. Further, in the conventional method, the film feeding speed is reduced when the difference between both outputs reaches a predetermined value close to zero; and when both outputs become equal, the film is stopped to position the desired frame of the film at the projection or viewing station.
In conventional devices for carying out the above-described conventional procedures, complicated circuitry including an operation circuit computing the difference between two decimal counters and a speed control circuit has been necessary, and a considerable improvement in price and circuit construction has been desired.